The present invention relates to a sanitary napkin, or a similar article such as a disposable diaper or adult incontinent pad, which comprises a fluid absorbent pad enclosed within a moisture permeable wrapper covering at least one major face and having a flexible mositure impervious barrier essentially covering the other major face of the article. The moisture impervious barrier is formed as a longitudinal envelope which may be used to enclose the pad so as to maintain cleanliness while carrying the article or for sanitary and discreet disposal after use.
The problems associated with sanitary and discreet disposal of single use articles such as diapers and sanitary napkins have been well recognized since their advent. Various proposed solutions to this disposal problem are well documented in the patent literature of the last 35 years. These proposed solutions have followed two general paths. To refer specifically to sanitary napkins, one route has been to enclose the product in a separate bag or envelope which can be retained during use and used later for disposal. A related approach, and apparently the only one which has seen any significant commercial use, is simply to supply an adequate number of disposal bags as entirely separate items included within a package of sanitary napkins. The following U.S. pat. Nos. are exemplary of this approach: Pickens, U.S. Pat. No. 2,750,033; Wallace, U.S. Pat. No. 2,766,927; Srinivasan et al, U.S. Pat. No. 3,973,567; Swanson et al, U.S. Pat. No. 4,556,146; and Newman, U.S. Pat. No. 4,648,513.
Izzo, in United States Pat. No. 4,493,713, shows a disposable diaper supplied with a removal disposal bag covering the body contacting side of the product. This is perforated at each end and must be removed before use. The bag is then retained separately for disposal whether the diaper is changed.
The use of a separate disposal bag or envelope is in most cases quite simple and inexpensive. It does have the disadvantage that the woman using the product must retain the disposal device and have it handy when needed. This is almost always somewhat inconvenient and sometimes impossible. For this reason a second approach has been taken in which an envelope or some other structure intended for later use for disposal is made integral with the pad itself and is retained thereon during use. After use, the soiled pad is totally, or almost so, enclosed within the disposal means before being discarded. In virtually all cases the disposal means is located on the major face of the pad opposite the body facing side. In many cases, although certainly not all, it serves the additional function as a moisture impervious barrier to prevent strikethrough and subsequent soiling of the wearer's clothing.
Evolution of the integral disposal means has followed evolution of sanitary napkins themselves. During the 1970s the tab and belt suspension system in use to that time was superseded by the use of adhesive areas on the back surface of the napkin. These bonded lightly to the undergarments of the wearer to hold the pad in place during use. The nature of suggested integral disposal devices necessarily had to be compatible with this rather basic change in product construction.
The following United States patents can be considered exemplary of attempts at making sanitary napkins with an integral disposal envelope or similar structure. Lane, in U.S. Pat. No. 3,024,788, shows a tab type napkin in which an invertible bag forms one end tab. Elmore, in U.S. Pat. No. 3,035,578, shows a detachable folded flat sheet of moisture impervious material covering the entire garment facing surface of a sanitary napkin. An alternate version includes a separate tucked-in disposal bag inserted in a silt in the napkin wrapper.
Kargul, in U.S. Pat. No. 3,230,956, shows a longitudinal envelope on the garment facing side of a sanitary napkin. This is fan folded along each longitudinal edge and has a centrally located tear strip. Very similar structures are shown by Ryan, in U.S. Pat. No. 4,551,145 and Tucker, U.S. Pat. No. 4,605,403. Tucker also shows a separate embodiment having a tucked-in folded disposal bag very similar to that described earlier by Elmore. Alvarado et al, in U.S. Pat. No. 4,581,027, shows a closely-related structure in which the envelope is not longitudinally pleated but, instead, is wrapped up around each edge of the pad.
Frazer, in U.S. Pat. No. 3,604,423, and Black, in U.S. Pat. No. 4,182,336, shows longitudinally oriented wedged-shaped envelopes made by incorporating triangular side gussets. Black's envelope additionally is transversely fan folded to allow adequate exposure of adhesive strips for bonding the pad to an undergarment.
Robinson, in U.S. Pat. No. 3,274,999, includes a trapezoidal fan folded envelope, similar to those of Black or Frazer, but oriented so as to have the opening parallel to a longitudinal edge of the napkin. The folded envelope is not coextensive with the garment-facing surface and could not effectively prevent strikethrough.
Finally, in the integral envelope group, U.S. Pat. No. 4,402,689 to Baum, should be noted. This uses a simple longitudinal wrap, open at the ends.
U.S. Pat. No. 3,626,945 to Mobley and U.S. Pat. No. 4,380,450 to Reich, might also be mentioned as a third general type of solution to the disposal problem. Each of these sanitary napkins has an adhesive spot located at one end which can be uncovered after use. The soiled napkin is tightly rolled and the adhesive spot serves to retain it in this form.
Of remote relevance to the present invention are U.S. Pat. Nos. 3,096,765 to Cornwell and 3,424,163 to Gravdahl. These principally relate to shields to prevent strike through but neither inventor suggests the use of the shield for later disposal.
Despite the many attempts listed above to provide an answer to the disposal problem, the only approach which has any commercial success to date is the use of an entirely separate wrapper which must then be retained and kept available for disposal after use. The inconvenience of this approach has already been noted, although it does in some cases address one problem which has not heretofore been discussed. This is the matter of a woman who chooses to carry one or more sanitary napkins in her purse, an environment where it almost impossible to maintain them in clean condition unless they are somehow wrapped or packaged. While the separate envelope solves this problem, it does nothing to help with ultimate disposal unless the envelope itself can be retained and kept convenient. To the knowledge of the present inventor, none of the inventions have been commercially successful where a disposal envelope has been made integral with the pad. Further, these do not address the problem of maintaining cleanliness before use.
The present invention is a new and simple approach to maintaining cleanliness of a sanitary napkin or related product prior to use and of providing a simple, convenient, immediately available, discreet and sanitary means for disposing of the product after use.